The San Francisco 49ers will be without tight end George Kittle, who will miss Monday night's game against the Seahawks as he continues to deal with knee and ankle injuries. Ross Dewlley will replace Kittle in the starting lineup. 

With Kittle's status in question leading up to the game, the 49ers activated tight end Garrett Celek off the Reserve/Physically Unable to Perform List leading up to their "Monday Night Football'' matchup with the Seattle Seahawks. To make room for Celek on the active roster, the Niners waived corner Dontae Johnson. 

Celek was placed on the PUP list back on August 31 after undergoing offseason back surgery and has been out ever since. He returned to practice last week and noted last Saturday that he's still shaking off some rust, but is making solid progress. 

"I still feel like I'm not quite in the game speed that I normally am," Celek said, via The San Francisco Chronicle, "but I'm getting there for sure. My legs feel good. My back feels good."

Celek is the second longest tenured player on the 49ers roster, arriving to town back in 2012 as an undrafted free agent out of Michigan State. In 86 regular season games with San Francisco, the 31 year old has totaled 82 receptions for 1,104 yards and 12 touchdowns. 

While the 49ers still have several weapons, losing Kittle is significant considering that he has more than twice as many catches than the team's second leading receiver. Except quarterback Jimmy Garoppolo to look more to receiver Emmanuel Sanders, who caught seven passes for 112 yards and a touchdown in San Francisco's last outing, a Week 9 victory over Arizona.